Sensor network navigation without locations

We propose a pervasive usage of the sensor network infrastructure as a cyber-physical system for navigating internal users in locations of potential danger. Our proposed application differs from previous work in that they typically treat the sensor network as a media of data acquisition while in our navigation application, in-situ interactions between users and sensors be- come ubiquitous. In addition, human safety and time factors are critical to the success of our objective. Without any pre- knowledge of user and sensor locations, the design of an effective and efficient navigation protocol faces non-trivial challenges. We propose to embed a road map system in the sensor network without location information so as to provide users navigating routes with guaranteed safety. We accordingly design efficient road map updating mechanisms to rebuild the road map in the event of changes in dangerous areas. In this navigation system, each user only issues local queries to obtain their navigation route. The system is highly scalable for supporting multiple us- ers simultaneously. We implement a prototype system with 36 TelosB motes to validate the effectiveness of this design. We fur- ther conduct comprehensive and large-scale simulations to ex- amine the efficiency and scalability of the proposed approach under various environmental dynamics.